Process for weighting silks



Patented Dec. 15, 1925.

UNITED STATES PATENT OFFICE.

ANTHONY PEPPER, 0F PATERSON, NEW JERSEY.

PROCESS FOR WEIGHTING SILKS.

No Drawing.

State of New Jersey, have invented certainnew and useful Improvements inProcesses for Weighting Silks, of which the following is aspecification.

This invention relates to a process for weighting silks by means ofchemical compounds.

In the production of' silk fabrics -1t is necessary to treat the silksbefore dyeing with a chemical which will give suffic1ent weight to thefabric and which Wlll not be objectionable because of its effect uponthe skin of a wearer. It is well known that the halogencompounds of tinhave been employed for the purpose but due to the fact that it isdifficult to obtain astannic compound free of impurities such compoundshave therefore been very unsatisfactory. Lead acetate has also beensuggested but is also considered objectionable due to the fact that whenthe silk containing such acetate comes in contact with the skin it willcause irritation.

It is an object of the present invention to provide a process in which acompound of tin and of lead may be employed for weighting the silk whichwill have none of the objectionable features ordinarily found and inwhich the materials after being treated with stannic chloride are thentreated to a solution of sodium phosphate. After washing the goods thustreated are at a predetermined temperature placed in a weak solution ofacetic acid. A solution of lead acetate is then applied and afterwashing the materials are placed in a cold solution of sodium phosphate.

A further object of the invention is the provision of a process in whichsilk fabrics are treated with a compound of tin after which the goodsare placed in a solution of sodium phosphate at a predeterminedtemperature for approximately one hour. After the goods have been washedthey are treated with a warm and weak solution of acetic acid and afterwashing they are successively treated with a lead acetate solution andcold sodium hosphate solution.

This invention will be best understood from a consideratlon of thefollowing de- Application filed August n 1925 Serial No. 50,271.

-tailed description nevertheless it is to be understood that theinvention is not confined to the disclosure, being susceptible of suchchanges and modifications which shall define no material departure fromthe salient features of the invention as expressed in the appendedclaims.

In carrying out my invention a solution of stannic chloride SnCl at 20Baum is prepared and the silk fabrics are placed in the solution forapproximately one hour and after such time they are removed and washedin order to remove the excess halo-gen compound.

After the washing process the'fabrics are placed in a solution of sodiumphosphate of 7 Baum and at a temperature of 150 B. where the fabrics arepermitted to remain for approximately one hour when they are removed andwashed in clear water. The steps in the above noted process are repeatedapproximately three times.

After the last washing the fabrics are then placed in a 3% solution ofacetic acid and at a temperature of 160 F. The fabrics are allowed toremain in this solution for approximately one-halfshour when they aretreated with cold water and are then placed in a lead acetate solutionat 150 F. and permitted to remain there forone our. The lead acetate isthe normal or diacetate of lead known as sugar of lead and having anempirical formula Pb(C H O 2. The temperature of the acetate solution ismaintained at 150 F. and the solution isapproximately of 2 to 3 degreesaum. The fabrics are permitted to rema'n in the solution for one hourafter w ich they are washed. They are then placed in a cold sodiumphosphate solution for one-half hour when they are removed and dried andthen are ready for dyeing.

By the treatment of the stannic chloride and the treatment of the leadacetate with sodium phosphate injurious effects of the some of theacetate of lead is converted into tribasic lead phosphate Pb .,(PO,) 2.The tribasic phosphate salt of lead maybe formed when a small quantityof sodium phosphate is added to an excess of lead acetate.

The step in the processby which the silk fabrics are treated withstannic chloride and sodium phosphate with the number of necessarywashings is the usual method for preliminarily treating silk fabricsbefore dyeing. When the fabrics are treated with a weak solution ofacetic acid and the lead acetate the fabrics absorb a predeterminedquantity of the lead acetate so that when the sodium phosphate is placedin solution and the fabrics are treated an insoluble salt of lead isformed which will not be acted upon by the perspiration and therebyafiect the skin of the wearer.

What I claim is:

1. A process for weighting silk fabrics which comprises placing thefabrics in a solution of stannic chloride of 20 Baum for approximatelyone hour, then washing the fabrics, treating the washed fabrics with asolution of sodium phosphate of 7 Baum at atemperature of 150 F. forapproximately one hour, then washing the fabrics, treating the washedfabrics with a 3% solution of acetic acid at 160 F. for one half hour,washin the fabric with cold Water, treating the fabric with a solutionof lead acetate of approximately 3 Baum at a temperature of 150 F. forone hour and then after washing treating the fabrics with a coldsolution of sodium phosphate for one half hour.

'2. A process for, weighting silk fabrics which comprises placing thefabric in a solution of stannic chloride for one hour then washing thefabric, treating the washed solution of lead acetate for approximatelyone hour, and then washing said fabric and treating the same with a coldsolution of sodium phosphate for approximately onehalf hour.

3. A process for weighting silk fabrics which comprises treating thefabrics with a solution of stannic chloride, then washing the fabrics,treating the washed fabrics with a solution of sodium phosphate, thenwashing the fabrics, treating the washed fabrics with a solution ofacetic acid, then washing the fabrics with cold water, treating thefabrics with a solution of lead acetate, then washing the fabrics andtreating the same with a cold solution of sodium phosphate.

4. A step in. the process for weighting silk'fabrics which comprisestreating Silk fabrics with a weak solution of acetic acid forapproximately one half hour, Washing the fabrics thus treated in coldwater, then treating the washed fabrics with a solution of lead acetatefor approximately one hour, washing said fabrics, and then treating saidfabrics with a cold solution of sodium phosphate for approximately onehalf hour.

5. A step in the process for weighting silk fabrics which comprisestreating silk fabrics with a hot solution of acetic acid forapproximately one-half hour, washing said fabrics in cold water and thentreating the fabrics with a hot solution of lead acetate ofapproximately 3 Bauln for approximately one hour, then washing thefabric and treating the same with a cold solution of sodium phosphatefor approximately one half hour.

6. A step in the process for weighting silk fabrics which comprisestreating s lk fabrics with a Weak solution of acetic acid,

washing the fabrics thus treated in cold water, then treating the washedfabrics with a solution of lead acetate, washing said fabrics, and thentreating saidfabrics with a cold solution of sodium phosphate.

7 A step in the process for weighting silk fabrics which comprisestreating silk fabrics with a weak solution of acetic acid,

treating the fabrics with a solution of lead acetate, and then treatingthe fabrics with a solution of sodium phosphate.

ANTHONY PEPPER.

